R/labeller.R

In ggforce: Accelerating 'ggplot2'

#' A labeller function to parse TeX syntax
#'
#' This function formats the strip labels of facet grids and wraps that contains
#' TeX expressions. The latex2exp package must be installed.
#'
#' @seealso [ggplot2::labeller], [latex2exp::TeX()]
#'
#' @inheritParams ggplot2::label_parsed
#' @inheritDotParams ggplot2::label_parsed -labels
#'
#' @examples
#' # requires latex2exp package be installed
#' if (requireNamespace("latex2exp", quietly = TRUE)) {
#'   library(ggplot2)
#'   d <- data.frame(x = 1, y = 1, facet = "$\\beta$")
#'   ggplot(d, aes(x, y)) +
#'     geom_point() +
#'     facet_wrap(~ facet, labeller = label_tex)
#' }
#' @importFrom ggplot2 label_parsed
#' @export
label_tex <- function(labels, ...) {
  check_installed('latex2exp', 'to parse tex equations')
  label_parsed(
    data_frame0(!!!lapply(labels, latex2exp::TeX, output = "character")),
    ...
  )
}